Rome, April 15 - Italian House Speaker Laura Boldrini on Monday convened parliament and representatives of the nation's regional governments to meet on Thursday, April 18, to start electing a new president of Italy. The widely expected move comes as Italy's outgoing head of state, Giorgio Napolitano, nears the end of his seven-year term as the main custodian of Italy's Constitution. Napolitano was elected to his non-executive post on May 15, 2006. It is still unclear who his replacement is likely to be as Italy struggles with a hung parliament. Italy has been in a state of political deadlock since February's inconclusive general election, in which the centre left finished ahead of ex-premier Silvio Berlusconi's centre-right coalition, but did not win a working majority. Berlusconi has said he might be willing to consider backing a presidential candidate from the centre-left Democratic Party (PD) if it drops its refusal to form a broad government coalition with his People of Freedom (PdL) party. Centre-left coalition leader and PD head Pier Luigi Bersani has so far rejected the PdL's calls to form a grand coalition, even though Bersani has failed to win support from the anti-establishment 5-Star Movement (M5S), which holds the balance of power in parliament. Beppe Grillo's M5S has shortlisted nine presidential candidates, including former centre-left premier Romano Prodi, former European commissioner Emma Bonino and Nobel Literature Laureate Dario Fo, who has already said he does not want to be head of state. Romano Prodi is also popular with the centre-left, but Berlusconi has vowed to scupper Prodi's prospects.